Germline development is a highly evolutionarily conserved process, which, ultimately, gives rise to either sperm or eggs. One potential regulator of this process is the tumor suppressor gene p53. During gametogenesis, it has been proposed that p53 functions in surveillance of germ cells by mediating apoptosis and cell cycle arrest. In addition, it has been recently reported that the Drosophila homolog of p53 (Dmp53) is expressed in germ cells prior to the onset of gametogenesis. This expression pattern is consistent with that seen in organisms ranging from clams to humans. Therefore, we propose that p53 may also perform a role in germline surveillance during earlier stages of development to test this hypothesis, we intend to use Drosophila Melanogaster, as a model system to study the role of p53 during early germ cell development. Specifically, we will undertake (1) a thorough characterization of Dmp53 expression during germline development, including an analysis of somatic cues regulating its expression, (2) an analysis of Dmp53's impact on apoptosis, cell cycle progression and germ cell maturation during germline development, and (3) an examination of Dmp53's ability to directly mediate germline surveillance. Together, these studies will provide insight into the role of Dmp53 during germ cell development and germline selection.